Growing and Using Ma Huang (Chinese Ephedra) for Asthma

I used to brew tea of ma huang I purchased in a health food store for my severe asthma. I am delighted to see that Richter's now offers seeds of this important herb. I live in a very cold climate (zone 4b), with winter temperatures to -20 or -25 F. I realize I will have to grow it in pots. My questions are:
1. How many plants do you think I would have to grow in order to have perhaps a cup of the dried herb stored? (If I know that, I can figure out how much I need for each winter.)
2. How do I prepare the plant for use in a tea for asthma? I saw what it looked like when I bought it before, and it seemed to be basically dried loose-leaf above-ground plant material – very little processing other than drying. Is there more to it than this? Or was I looking at rhizomes or something instead of above-ground plant material?
3. What sort of light and heat will I have to provide the ma huang indoors for it to thrive well enough to have good medicinal qualities? Will I be able to set it outside in the summers? It is hot and dry here then. Would it be better to just keep it inside if it's potted?
4. And finally, when I harvest it to put up for winter use, if I leave a large portion of each plant will it continues to grow? Or is it an annual?

1. It's hard to tell how many plants you need because the products of each plant may vary with different growing condition. Because you are going to grow it in the pot, which limits its growing potential, therefore it is difficult to estimate the amount you need. I suggest you get one or two packages from Richters for trial.
2. You were right about the observation. You weren't looking at rhizomes; it is the stems and leaves of the plant. The preparation is very simple for this herb. When you want to prepare it, first you need to pick out the withered stems; and then, clean the lignified stems and the roots; the next step is to rinse with water and give it an airing. Afterwards you can cut it into 1-1.5 cm, and dry it.
3. It prefers dry, well-drained location with full sun exposure. So you will be able to set it outside in the summers.
4. Yes it is annual, so you will have to buy the seeds every year.
Note: it is not used excessively and contraindicated in conditions of spontaneous perspiration due to exterior deficiency, night sweating due to yin deficiency, asthemia-dyspnea and high blood pressure.